1. Field of the Invention
The present invention relates to an electron-emitting device, an electron source using the device, and an image display apparatus. Moreover, the present invention relates to an information display apparatus such as a television, which receives a broadcast signal such as television broadcasting and performs the display and the reproduction of image information, character information and audio information, which are included in the broadcast signal.
2. Description of Related Art
The producing process of a conventional surface conduction electron-emitting device is schematically shown using FIGS. 24A to 24D. First, a pair of auxiliary electrodes 2 and 3 is formed on a substantially insulative substrate 1 (FIG. 24A). Next, the pair of auxiliary electrodes 2 and 3 is connected with an electroconductive film 4 (FIG. 24B). Then, the processing called as “energization forming”, which forms a first gap 7 at a part of the electroconductive film 4 by applying an voltage between the pair of auxiliary electrodes 2 and 3, is performed (FIG. 24C). The “energization forming” processing is a process of flowing a current in the electroconductive film 4 to form the first gap 7 at a part of the electroconductive film 4 with the Joule heat generated by the current. A pair of electrodes 4a and 4b opposed to each other with the first gap 7 put between them is formed by the “energization forming” processing. Then, the processing called as “activation” is preferably performed. The “activation” processing schematically includes the process of applying a voltage between the pair of auxiliary electrodes 2 and 3 in a carbon containing gas atmosphere. By the processing, carbon films 21a and 21b, which are electroconductive films, are formed on the substrate 1 in the first gap 7 and on the electrodes 4a and 4b in the vicinity of the first gap 7 (FIG. 24D). An electron-emitting device is formed by the above process.
FIG. 8A is a plan view schematically showing the electron-emitting device after performing the “activation” processing. FIG. 8B is a schematic sectional view along a line B-B′ of FIG. 8A, and is fundamentally the same as FIG. 24D. In FIGS. 24A to 24D, the members denoted by the same reference numerals as those in FIGS. 8A and 8B denote the same members as those in FIGS. 8A and 8B. When the electron-emitting device is made to emit electrons, the potential applied to one of the auxiliary electrode 2 and 3 is made to be higher than the potential applied to the other one. By applying voltages to the auxiliary electrodes 2 and 3 in this manner, a strong electric field is generated at a second gap 8. As a result, it is considered that electrons are emitted from many positions (a plurality of electron-emitting regions) of the portions constituting the outer edge of the second gap which portions are edge ends of the carbon film 21a or 21b connected to the auxiliary electrode 2 or 3 on the lower potential side.
Japanese Patent Application Laid-Open No. H07-201274, Japanese Patent Application Laid-Open No. H04-132138, Japanese Patent Application Laid-Open No. H01-279557, Japanese Patent Application Laid-Open No. H02-247940 and Japanese Patent Application Laid-Open No. H08-96699 disclose techniques controlling the positions of the gaps by controlling the shapes of the auxiliary electrodes 2 and 3 and the electroconductive film 4, and the like.
An image display apparatus can be configured by opposing a substrate equipped with an electron source composed of an arranged plurality of such electron-emitting devices therein and a substrate equipped with a light-emitting film made of a phosphor or the like, and by maintaining the space between the substrates in vacuum.